N-propyl bromide is a product which has considerable industrial importance, particularly as a solvent for cleaning and degreasing replacing ODS (such as: 1,1,1-TCE, CFC-113) used in precision cleaning electronic defluxing, metal cleaning, adhesives, coatings, products and solvent applications.
In principle, n-propyl bromide is the product of a reaction between hydrobromic acid HBr and n-propanol. However, depending on the way in which the reaction is carried out, the result may be unsatisfactory, e.g., as to conversion and purity of the product, and most particularly, because of the contamination with by-products, especially isopropyl bromide.
Schematically, the reaction is as follows:HBr+CH3—CH2—CH2OH→CH3—CH2—CH2Br+H2O.
In prior art processes, the n-propyl bromide form contains a weight percentage of isopropyl bromide which may approach and even exceed 1%. (All the percentages in this specification and claims are by weight, unless otherwise indicated.) Said percentage is higher than desirable, because isopropyl bromide has a proven toxic effect, and it is a purpose of this invention to provide a process for the preparation of n-propyl bromide from HBr and n-propanol wherein the resulting n-propyl bromide contains amounts of isopropyl bromide equal or below 0.1%, preferably equal or below 0.05%, viz. equal or below 500 ppm.
It is another purpose of this invention to provide such a process which can be carried out continuously or in batch procedure.
It is a still further purpose of this invention to provide such a process which has a high conversion rate.
Other purposes and advantages of this invention will appear as the description proceeds.